The present invention relates to a system for electrically coupling a charging device with an electrical supply unit.
Cableless electrical devices, hand-held power tools in particular, with a mains-independent voltage supply for the electric motor have enjoyed extensive use in recent years, because independence from the voltage network offers many advantages for the handling of hand-held power tools of this type. The rechargeable batteries for voltage supply are integrated in the hand-held power tool or they are attached to the housing of the hand-held power tool as a rechargeable battery pack. To charge the rechargeable battery pack, the hand-held power tool or the rechargeable battery pack are coupled with a charging device. It is known from the related art that, in order to charge the rechargeable battery, the rechargeable battery pack is separated from the electrical device or it remains connected with the electrical device. If the rechargeable batteries are permanently integrated in the electrical device, the electrical device can be placed on the charging device, where it is held in place by gravity.
Publication DE 102 12 750 A, e.g., makes known a hand-held power tool such as a drill or a drill/driver, to the housing of which a rechargeable battery pack system can be attached. Snap-in elements are provided for mechanically connecting the housing with the rechargeable battery pack system, and contact elements are provided for the electrical connection. The rechargeable battery pack can be attached, e.g., at the base of the handle of the hand-held power tool. At least one lateral surface of the rechargeable battery pack is designed as a support surface, thereby enabling the hand-held power tool to be placed on a flat surface when the rechargeable battery pack system is attached.
Known electrical devices powered by rechargeable battery packs, hand-held power tools in particular, have the disadvantage that the process of charging the rechargeable battery pack can also take place, under certain circumstances, when the rechargeable battery pack or the electrical device are not fully engaged in the charging device. Under certain circumstances, it is therefore possible that the charging process will take place in an uncontrolled manner. When this happens, it is not ensured that the rechargeable battery pack will be in a fully recharged state after the electrical device has spent a certain amount of time in the charging device.